scholarly journals Multimodal assessment of right ventricle overload-metabolic and clinical consequences in pulmonary arterial hypertension

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Remigiusz Kazimierczyk ◽  
Lukasz A. Malek ◽  
Piotr Szumowski ◽  
Stephan G. Nekolla ◽  
Piotr Blaszczak ◽  
...  

Abstract Background In pulmonary arterial hypertension (PAH) increased afterload leads to adaptive processes of the right ventricle (RV) that help to maintain arterio-ventricular coupling of RV and preserve cardiac output, but with time the adaptive mechanisms fail. In this study, we propose a multimodal approach which allows to estimate prognostic value of RV coupling parameters in PAH patients. Methods Twenty-seven stable PAH patients (49.5 ± 15.5 years) and 12 controls underwent cardiovascular magnetic resonance (CMR). CMR feature tracking analysis was performed for RV global longitudinal strain assessment (RV GLS). RV-arterial coupling was evaluated by combination of RV GLS and three proposed surrogates of RV afterload—pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC). 18-FDG positron emission tomography (PET) analysis was used to assess RV glucose uptake presented as SUVRV/LV. Follow-up time of this study was 25 months and the clinical end-point was defined as death or clinical deterioration. Results Coupling parameters (RV GLS/PASP, RV GLS/PVR and RV GLS*PAC) significantly correlated with RV function and standardized uptake value (SUVRV/LV). Patients who experienced a clinical end-point (n = 18) had a significantly worse coupling parameters at the baseline visit. RV GLS/PASP had the highest area under curve in predicting a clinical end-point and patients with a value higher than (−)0.29%/mmHg had significantly worse prognosis. It was also a statistically significant predictor of clinical end-point in multivariate analysis (adjusted R2 = 0.68; p < 0.001). Conclusions Coupling parameters are linked with RV hemodynamics and glucose metabolism in PAH. Combining CMR and hemodynamic measurements offers more comprehensive assessment of RV function required for prognostication of PAH patients. Trial Registration: NCT03688698, 09/26/2018, retrospectively registered; Protocol ID: 2017/25/N/NZ5/02689

2015 ◽  
Vol 240 (10) ◽  
pp. 1362-1372 ◽  
Author(s):  
Ji Wu ◽  
Xiaoju Luo ◽  
Yuanyuan Huang ◽  
Yun He ◽  
Zhixian Li

The continuous changes in pulmonary hemodynamic properties and right ventricular (RV) function in pulmonary arterial hypertension (PAH) have not been fully characterized in large animal model of PAH induced by a carotid artery–jugular vein shunt. A minipig model of PAH was induced by a surgical anastomosis between the left common carotid artery and the left jugular vein. The model was validated by catheter examination and pathologic analyses, and the hemodynamic features and right-ventricle functional characteristics of the model were continuously observed by Doppler echocardiography. Of the 45 minipigs who received the surgery, 27 survived and were validated as models of PAH, reflected by mean pulmonary artery pressure ≥25 mmHg, and typical pathologic changes of pulmonary arterial remodeling and RV fibrosis. Non-invasive indices of pulmonary hemodynamics (pulmonary artery accelerating time and its ratio to RV ventricular ejection time) were temporarily increased, then reduced later, similar to changes in tricuspid annular displacement. The Tei index of the RV was elevated, indicating a progressive impairment in RV function. Surgical anastomosis between carotid artery and jugular vein in a minipig is effective to establish PAH, and non-invasive hemodynamic and right-ventricle functional indices measured by Doppler echocardiography may be used as early indicators of PAH.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Oliver ◽  
S.F Rocha ◽  
M Spaczynska ◽  
D.V Lalama ◽  
M Gomez ◽  
...  

Abstract Background Endothelial dysfunction is one of the most important hallmarks of pulmonary arterial hypertension (PAH). This leads to anomalous production of vasoactive mediators that are responsible for a higher vascular tone and a subsequent increase in pulmonary artery pressure (PAP), and to an increased vascular permeability that favors perivascular inflammation and remodeling, thus worsening the disease. Therefore, preservation of the endothelial barrier could become a relevant therapeutic strategy. Purpose In previous studies, others and we have suggested the pharmacological activation of the β3-adrenergic receptor (AR) as a potential therapeutic strategy for pulmonary hypertension (PH) due to left heart disease. However, its potential use in other forms of PH remain unclear. The aim of the present study was to elucidate whether the β3-AR agonist mirabegron could preserve pulmonary endothelium function and be a potential new therapy in PAH. Methods For this purpose, we have evaluated the effect of mirabegron (2 and 10 mg/kg·day) in different animal models, including the monocrotaline and the hypoxia-induced PAH models in rats and mice, respectively. Additionally, we have used a transgenic mouse model with endothelial overexpression of human β3-AR in a knockout background, and performed in vitro experiments with human pulmonary artery endothelial cells (HPAECs) for mechanistic experiments. Results Our results show a dose dependent effect of mirabegron in reducing mean PAP and Right Ventricular Systolic Pressure in both mice and rats. In addition, the use of transgenic mice has allowed us to determine that pulmonary endothelial cells are key mediators of the beneficial role of β3-AR pathway in ameliorating PAH. Mechanistically, we have shown in vitro that activation of β3-AR with mirabegron protects HPAECs from hypoxia-induced ROS production and mitochondrial fragmentation by restoring mitochondrial fission/fusion dynamics. Conclusions This protective effect of mirabegron would lead to endothelium integrity and preserved pulmonary endothelial function, which are necessary for a correct vasodilation, avoiding increased permeability and remodeling. Altogether, the current study demonstrates a beneficial effect of the β3-AR agonist mirabegron that could open new therapeutic avenues in PAH. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Programa de Atracciόn de Talento, Comunidad de Madrid


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Allan K Alencar ◽  
Sharlene L Pereira ◽  
Arthur E Kummerle ◽  
Sharon S Langraf ◽  
Celso Caruso-Neves ◽  
...  

Pulmonary arterial hypertension (PAH) is characterized by enhanced pulmonary vascular resistance with subsequent remodeling and right ventricular hypertrophy. Vascular reactivity and ventricular function were investigated in rats with monocrotaline-induced PAH and treated with a new N-acylhydrazone derivative named as LASSBio-1359. METHODS: Protocols were approved by Animal Care and Use Committee at Universidade Federal do Rio de Janeiro. Male Wistar rats received a single i.p. injection of monocrotaline (MCT) (60 mg/kg) for PAH induction and were randomly divided in groups which were treated with: saline, vehicle and LASSBio-1359 (50 mg/kg p.o.). After 14 days of treatment, some parameters were evaluated: pulmonary acceleration time (PAT); right ventricular systolic pressure (RVSP); vascular reactivity to acetylcholine; expression of iNOS in pulmonary tissue; wall thickness of pulmonary artery (PAWT). Results: PAT (ms) was increased from 26.2 ± 2.8 to 41.3 ± 3.9 in PAH group treated with vehicle (n=8, p<0.05) and was reduced to 24.2 ± 1.7 when PAH group was treated with LASSBio-1359. RVSP (mmHg) increased from 26.0 ± 2.0 to 55.2 ± 2.3 in PAH group (p<0.05) but was similar to control after treatment with LASSBio-1359 (31.8 ± 2.3 mm Hg). Ratio of right ventricle and body weight (mg/g) was 0.66 ± 0.02, 1.63 ± 0.16 and 0.87 ± 0.10 for control, vehicle- and LASSBio-1359-treated PAH groups, respectively. PAH promoted ventricular dysfunction which was reduced by LASSBio-1359. The pulmonary artery maximum relaxation (%) was 57.3 ± 5.5, 43.6 ± 1.2 and 61.4 ± 8.4 for control, vehicle and LASSBio-1359-treated groups indicating that PAH promoted endothelium injury which was recovered by LASSBio-1359. iNOS expression in pulmonary tissue was increased from 0.48 ± 1.31 to 0.98 ± 3.14 in PAH group and reduced to 0.53 ± 1.83 in rats treated with LASSBio-1359. The PAWT (%) were increased from 74.1 ± 1.3 to 90.2 ± 2.7 in PAH group (p<0.05) but was 74.4 ± 1.3 when treated with LASSBio-1359. This compound showed an in vitro vasodilatory activity mediated by activation of adenosinergic A2A receptor. Conclusion: LASSBio-1359 reduced ventricular and vascular dysfunction in monocrotaline-induced PAH in rats indicating a possible new alternative to treat PAH.


2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
H Sato ◽  
Y Someya ◽  
M Nishiyama ◽  
W Satoh ◽  
K Kumasaka ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI, Grant-in-Aid for Early-Career Scientists. Background   Pulmonary arterial hypertension (PAH) remains a fatal disorder characterized by elevated pulmonary arterial pressure. Survival of the patients with PAH is determined from right ventricular (RV) function. CMR has become an attractive modality for following up and providing prognosis in such patients, and CMR feature tracking has been used as a newer useful parameter to assess RV function. However, it has not yet been determined whether CMR feature tracking can assess RV functional reserve in patients with PAH. Purpose We investigated whether CMR feature tracking can estimate RV functional reserve using a rat model with PAH. Methods  Rats were received injections with monocrotaline (MCT-rats, n = 19) or solvent (Ctr-rats, n = 5). Four weeks after the injections, we performed CMR on 7-T MRI scanner and imaged retrospective ECG-gated cine MR (16 phases/beat). RV ejection fraction (RVEF) and RV strain were analyzed before and after addition of 0.5∼3 nmol endothelin-1 (ET-1). After the measurements, we dissected trabeculae (length = 1.45 ± 0.07 mm, width = 334 ± 27 µm, thickness = 114 ± 6 µm) from the RVs of rat hearts. Trabeculae were electrically stimulated with 2-s intervals at extracellular Ca2+ of 0.7 and 2.0 mmol/L (24°C). Force and maximum dF/dt (dF/dtmax) were then measured using a silicon strain gauge in the absence and presence of 0.1 µM ET-1. Results  MCT-rats showed higher systolic RV pressure (RVP), lower RVEF, and lower RV global longitudinal strain (RVGLS) in CMR imaging and showed lower developed force and lower dF/dtmax in their trabeculae. Correlation between RVGLS and dF/dtmax was higher (r = 0.53, p &lt; 0.05) than that between RVEF and dF/dtmax (r = 0.24). In 5 MCT-rats with preserved RVEF (&gt;50%), RVGLS had already been reduced, suggesting that RVGLS is reduced earlier than RVEF. ET-1 increased developed force and dF/dtmax in trabeculae from MCT-rats (12.2 ± 5.7 to 17.4 ± 3.1 mN/mm2 and 0.08 ± 0.03 to 0.14 ± 0.06 mN/mm2/sec, respectively, n = 6), and ET-1 also increased RVP in MCT-rats and Ctr-rats (49.0 ± 19.3 to 59.7 ± 16.8 mmHg in MCT-rats, n = 6, 17.3 ± 7.5 to 20.4 ± 7.8 mmHg in Ctr-rats, n = 2). According to RV global circumferential strain (RVGCS) and RVEF, we could divide MCT-rats into three groups as follows: MCT-rats with reduced-RVGCS (&gt; -20%)/preserved-RVEF (&gt; 50%), MCT-rats with increased-RVGCS (&lt; -30%)/preserved-RVEF and MCT-rats with reduced-RVGCS/reduced-RVEF. ET-1 reduced RVGCS in MCT-rats with reduced-RVGCS/preserved-RVEF, while ET-1 did not change RVGCS in MCT-rats with increased-RVGCS/preserved-RVEF. MCT-rats with reduced-RVGCS/reduced-RVEF died after injection of ET-1.  In Ctr-rats, ET-1 did not change RVGCS and RVEF.  These results suggest that RVGCS can be useful to assess RV functional reserve. Conclusion  CMR feature tracking can estimate RV functional reserve earlier and more accurately than RVEF in rats with PAH.  RV strain may become an important parameter to assess RV functional reserve in patients with PAH.


Circulation ◽  
2020 ◽  
Vol 142 (15) ◽  
pp. 1464-1484 ◽  
Author(s):  
Junichi Omura ◽  
Karima Habbout ◽  
Tsukasa Shimauchi ◽  
Wen-Hui Wu ◽  
Sandra Breuils-Bonnet ◽  
...  

Background: Right ventricular (RV) function is the major determinant for both functional capacity and survival in patients with pulmonary arterial hypertension (PAH). Despite the recognized clinical importance of preserving RV function, the subcellular mechanisms that govern the transition from a compensated to a decompensated state remain poorly understood and as a consequence there are no clinically established treatments for RV failure and a paucity of clinically useful biomarkers. Accumulating evidence indicates that long noncoding RNAs are powerful regulators of cardiac development and disease. Nonetheless, their implication in adverse RV remodeling in PAH is unknown. Methods: Expression of the long noncoding RNA H19 was assessed by quantitative PCR in plasma and RV from patients categorized as control RV, compensated RV or decompensated RV based on clinical history and cardiac index. The impact of H19 suppression using GapmeR was explored in 2 rat models mimicking RV failure, namely the monocrotaline and pulmonary artery banding. Echocardiographic, hemodynamic, histological, and biochemical analyses were conducted. In vitro gain- and loss-of-function experiments were performed in rat cardiomyocytes. Results: We demonstrated that H19 is upregulated in decompensated RV from PAH patients and correlates with RV hypertrophy and fibrosis. Similar findings were observed in monocrotaline and pulmonary artery banding rats. We found that silencing H19 limits pathological RV hypertrophy, fibrosis and capillary rarefaction, thus preserving RV function in monocrotaline and pulmonary artery banding rats without affecting pulmonary vascular remodeling. This cardioprotective effect was accompanied by E2F transcription factor 1-mediated upregulation of enhancer of zeste homolog 2. In vitro, knockdown of H19 suppressed cardiomyocyte hypertrophy induced by phenylephrine, while its overexpression has the opposite effect. Finally, we demonstrated that circulating H19 levels in plasma discriminate PAH patients from controls, correlate with RV function and predict long-term survival in 2 independent idiopathic PAH cohorts. Moreover, H19 levels delineate subgroups of patients with differentiated prognosis when combined with the NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels or the risk score proposed by both REVEAL (Registry to Evaluate Early and Long-Term PAH Disease Management) and the 2015 European Pulmonary Hypertension Guidelines. Conclusions: Our findings identify H19 as a new therapeutic target to impede the development of maladaptive RV remodeling and a promising biomarker of PAH severity and prognosis.


2016 ◽  
Vol 311 (3) ◽  
pp. H689-H698 ◽  
Author(s):  
Sachindra Raj Joshi ◽  
Vidhi Dhagia ◽  
Salina Gairhe ◽  
John G. Edwards ◽  
Ivan F. McMurtry ◽  
...  

Heart failure, a major cause of morbidity and mortality in patients with pulmonary arterial hypertension (PAH), is an outcome of complex biochemical processes. In this study, we determined changes in microRNAs (miRs) in the right and left ventricles of normal and PAH rats. Using an unbiased quantitative miR microarray analysis, we found 1) miR-21-5p, miR-31-5 and 3p, miR-140-5 and 3p, miR-208b-3p, miR-221-3p, miR-222-3p, miR-702-3p, and miR-1298 were upregulated (>2-fold; P < 0.05) in the right ventricle (RV) of PAH compared with normal rats; 2) miR-31-5 and 3p, and miR-208b-3p were upregulated (>2-fold; P < 0.05) in the left ventricle plus septum (LV+S) of PAH compared with normal rats; 3) miR-187-5p, miR-208a-3p, and miR-877 were downregulated (>2-fold; P < 0.05) in the RV of PAH compared with normal rats; and 4) no miRs were up- or downregulated with >2-fold in LV+S compared with RV of PAH and normal. Upregulation of miR-140 and miR-31 in the hypertrophic RV was further confirmed by quantitative PCR. Interestingly, compared with control rats, expression of mitofusin-1 (MFN1), a mitochondrial fusion protein that regulates apoptosis, and which is a direct target of miR-140, was reduced in the RV relative to LV+S of PAH rats. We found a correlation between increased miR-140 and decreased MFN1 expression in the hypertrophic RV. Our results also demonstrated that upregulation of miR-140 and downregulation of MFN1 correlated with increased RV systolic pressure and hypertrophy. These results suggest that miR-140 and MFN1 play a role in the pathogenesis of PAH-associated RV dysfunction. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/mir140-and-right-heart-hypertrophy/ .


2020 ◽  
Author(s):  
Bahram Ghasemzadeh ◽  
Bahador Azizi ◽  
Simin Azemati ◽  
Mostafa Bagherinasab

Anesthetized patient management for pediatric patients with pulmonary arterial hypertension (PAH) is a major challenge. The aim of this study was to evaluate the ability of dexmedetomidine to reduce pulmonary arterial hypertension in patients with pulmonary arterial hypertension undergoing cardiac surgery. Sixty-six patients with pulmonary arterial hypertension underwent the study. Patients were randomly divided into two groups: group D received a dexmedetomidine injection in a dose of 1 μg/kg in the first hour and then decreased to 0.5 μg/kg/hr, injection continued after surgery until extubation in the post-anesthetic care unit (PACU). Group C received normal saline 0.9% in a similar volume. Pulmonary artery systolic pressure (PASP) and systemic systolic blood pressure (SSBP) were recorded during and after the surgery in the postanesthetic care unit. Needing vasodilators, sedatives, extubation time, and the length of ICU stay were recorded for all patients. Patients in the dexmedetomidine group showed a significant reduction in Pulmonary artery systolic pressure and Pulmonary artery systolic pressure/systemic systolic blood pressure rates during surgery and during the first 24 hours in the post-anesthetic care unit (P<0.001). The dexmedetomidine group, in comparison with the control group, needed a significantly lower dose of a vasodilator (P<0.001) and a lower dose of sedation (P<0.001). It is concluded that the use of dexmedetomidine during the surgery in children with pulmonary hypertension reduces pulmonary artery systolic pressure during and after the surgery.


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